The experiment was conducted to study the effect of black seeds (Nigella sativa L.) supplementation at two levels on broiler chickens. The tested responses in this study were growth change, weight gain, feed conversion, antibody production, carcass quality, liver and kidney functions, fat stability, economical evaluation and histopathological examination of liver, proventriculus and intestine. A total of 30-day-old broiler chicks were distributed into three experimental groups. The birds were fed a basal diet supplemented with 0.0%, 1%, or 2% black seed meal during the experimental period (13-45 days). The results showed that diet supplementation of black seed at the level 2% improved broiler performance, raised antibody response, improved feed conversion, increased oxidative stability of meat, modulate the cholesterol profile in the serum which can be reflected in the meat and make an advantage for human diets, and economically did not adversely affect the total costs of the diet.